1. Field of the Invention
The present invention relates to a new improved tilting coal nozzle burner apparatus for furnaces and boilers. More particularly, the present invention is directed to a burner for pulverized coal and other fuels having a nozzle structure at the outlet end of a primary coal/air conduit which is tiltable up and down relative to the central axis of the conduit and which has a plurality of outlet sections having swirl vanes therein which cause the primary coal/air streams exiting from adjacent nozzle sections to swirl in opposite directions. By adjusting the angle of tilt of individual burner nozzles on the walls of a furnace, an operator is better able to adjust the heat distribution and fuel burning process to obtain improved stem temperature control and boiler efficiency while reducing the formation of NO.sub.X and other gaseous emissions.
2. Background of the Prior Art
The new and improved burner and nozzle structure of the present invention is especially well adapted for use in turbulent furnaces such as that shown and described in U.S. Pat. No. 4,517,904, incorporated herein by reference and sold by the assignee herein under the trademark "TURBO."
U.S. Pat. No. 2,895,435 discloses a tilting nozzle for a fuel burner with a single nozzle structure and U.S. Pat. Nos. 4,252,069 and 4,274,343 disclose fuel burner structures having plural tilting nozzles for a single primary air and coal stream. Similarly, U.S. Pat. Nos. 4,304,196 and 4,434,747 disclose burner arrangements having plural tiltable nozzles for each primary air and coal stream in a vertically stacked array of the streams.
U.S. Pat. No. 5,392,720 discloses a flame retaining tiltable nozzle tip having vanes for causing swirling action of a primary air and coal stream.
U.S. Pat. No. 5,417,564 discloses a method for altering the firing pattern in a furnace utilizing non-tilting nozzles in vertically stacked combinations for directing the discharging coal and primary air streams to swirl in opposite directions.